Hexarelin is not an approved medicine in any jurisdiction, so no regulator has reviewed a dose for safety or effectiveness. The figures below record what published studies administered and what research and community sources report — data points, not a protocol for the reader.
The short answer
Hexarelin is one of the few peptides in this category where the studied subcutaneous doses and the commonly reported ones are in the same neighbourhood. Human studies used 1.5 µg/kg subcutaneously, two or three times daily (Maccario et al., Eur J Endocrinol 2002) — about 105 µg per dose for a 70 kg adult — and 2 µg/kg intravenously as a single acute challenge in the cardiac studies (Broglio et al., Eur J Pharmacol 2002). Community sources describe roughly 100 µg once or twice daily. The unusual thing about hexarelin is not the dose; it is that its response decline over weeks has been measured, which changes what a schedule is even for.
Doses used in published studies
1.5 µg/kg subcutaneously, two or three times in a day — six healthy young men, with 24-hour sampling every 20 minutes. Both schedules raised mean GH equally, by increasing secretory burst mass rather than burst frequency, and left IGF-1, prolactin, ACTH and cortisol unchanged over the same period (Maccario 2002). That two and three doses per day produced the same result is a directly relevant data point about diminishing returns.
Twice daily subcutaneously for 16 weeks — 12 healthy elderly volunteers; GH area under the curve fell from 19.1 to 10.5 µg/L/h over the study and returned to baseline four weeks after stopping (Rahim & Shalet, Growth Horm IGF Res 1998).
2 µg/kg intravenously, single dose — the cardiac studies, in 24 men with coronary artery disease during bypass surgery (Broglio 2002) and in a series of healthy, GH-deficient and cardiomyopathy patients (Broglio et al., Endocrine 2001).
Commonly reported research protocols
Research and community sources most often describe roughly 100 mcg per administration subcutaneously, one to two times daily, on an empty stomach, with short cycles — frequently a few weeks on and a comparable period off — cited far more consistently for hexarelin than for other peptides in this family, specifically because of the desensitisation data.
These figures document what is reported, not what is validated. No regulator, guideline or controlled study supports them as a protocol.
Why cycling is the central question for this peptide
For most research peptides, "cycling" is convention without measurement. For hexarelin there are numbers. Across 16 weeks of twice-daily subcutaneous dosing, GH area under the curve was 19.1 µg/L/h at baseline, 13.1 at week 1, 12.3 at week 4 and 10.5 at week 16 (p = 0.0003 overall). Four weeks after stopping, a further dose produced 19.4 — indistinguishable from baseline. The authors concluded that attenuation is "partial and reversible" (Rahim & Shalet 1998).
Three practical readings follow, all descriptive rather than prescriptive. Most of the loss happened in the first week, not gradually across the four months. A month off restored the full response. And desensitisation is not confined to GH: after a single day of subcutaneous dosing, an intravenous challenge produced a blunted GH response and an abolished ACTH and cortisol response (Maccario 2002) — so a stimulation test performed on someone recently dosed will not read accurately.
How it is administered
Hexarelin ships as a lyophilised powder requiring reconstitution with bacteriostatic water before subcutaneous injection. Two failure modes account for most dosing errors:
Reconstitution sets the dose, not the label. How much diluent is added determines concentration; the volume drawn is read in syringe units, which are routinely misread as micrograms.
Weight matters at this potency. The studied dose was weight-based at 1.5 µg/kg. A flat 100 µg is close to that for a 70 kg adult and roughly 40% above it for someone of 50 kg.
Why oversight matters
Hexarelin carries the general secretagogue considerations — glucose handling, fluid retention, IGF-1 elevation, and the unresolved long-term questions a class review flagged, including a call for evaluation of cancer incidence and mortality with long-term use (Sigalos & Pastuszak, Sex Med Rev 2018).
It also carries one that is specific to it. Hexarelin acts on CD36 in cardiac tissue and acutely changes contractility and coronary vascular tone in humans at microgram-per-kilogram doses (Bodart et al., Circ Res 2002; Broglio 2002). Those studies were done under anaesthesia with invasive haemodynamic monitoring — the setting that makes an acute cardiac effect observable rather than surprising. Nothing describes what repeated dosing does to a heart over months.
Hexarelin is prohibited in sport at all times under WADA section S2, with validated urine assays for both parent compound and metabolites (Semenistaya et al., Drug Test Anal 2015).
See also hexarelin side effects and the research and evidence overview.
Sport & Anti-Doping Warning
Hexarelin is another potent GHRP-family peptide that anti-doping laboratories monitor; it appears in WADA-target lists and in research focused on detecting GH secretagogue misuse.
Although less well-known than GHRP-2 or GHRP-6 in the media, hexarelin is handled the same way under anti-doping rules and remains prohibited.